13 January 2010

Rebuilding Haiti

The massive earthquake that Haiti suffered yesterday, close to its capital city Port Au Prince, combined with hurricane and flood related damage from two years ago, has left this country, with the lowest GDP per capita in the Western hemisphere, about ten million people, and about the land area of Massachusetts on half of the island of Hispaniola, with an infrastructure crisis.

Over the lifespan of the buildings that Haiti will construct to replaces those that have been destroyed in the last couple of years, it can expect another major earthquake (this is the third very bad one is a couple hundred years or so), and many serious hurricanes. Its low lying coastal areas are also at high risk of inundation as global sea levels rise in connection with global warming. The earthquake risk in a coastal area also implies a tsunami risk.

So, Haiti needs a rebuilding solution that is resistant to these multiple serious predictable future tragedies, and yet is also cheap. Given local economics, solutions that have high labor costs and low material and professional costs are favored over those that have proportionately low labor costs and high material and professional costs.

Also, in the wake of a devastating disaster that did great damage to government buildings, likely leaving public administration in disarray in a place where government corruption and inefficiency was already a problem, so any building codes or land use reforms need to be implemented in ways that have minimal red tape and easy enforcement.

What makes sense?

Two ideas that come immediately to mind are legal barriers to construction of two or more story structures, and barriers to construction at low elevations and in flood plains. These kinds of buildings are especially vulnerable, I suspect.

The legal barriers could be as simple as requiring these high risk buildings to be fully insured by a solvent insurance company in a long term contract, while allowing single story, low flood risk buildings to be built without proof of insurance. These limitations can be imposed with a map and elementary visual inspect of plans and a tiny amount of paperwork, while reducing the overall risks involved in the new construction. This also discourages high risk construction, if even part of the discouragement comes in the form of bribes to local officials rather than compliance with the actual rules, by making construction of this type more expensive.

So what about the low risk buildings? What kind of cheap, labor heavy, one story, simple design is least vulnerable to earthquakes and hurricanes?

I can imagine, at least, a couple of approaches. The historic Japanese/Polynesian approach, which is to build flimsy (almost disposable) housing and then to create save havens where people can take shelter, or a "build for the centuries" approach that makes simple but tough buildings with some give that allows them to survive earthquakes while resisting hurricanes.

The first approach fights earthquakes by being light enough to cause few injuries and trap few people if it collapses, and is intended to be defeated by and rebuilt following hurricanes which come with enough warning to allow people to seek shelter.

For the second approach I would imagine something like walls consisting of a thick sloping mounds of pebbles and dirt, lightly and not pressure packed, with an easily rebuilt stucco or plaster coating to keep out rain, wind and insects; windows arranged so that there are windowless areas to the structure for safety in hurricanes; and a relatively light, flexible material for a roof like bamboo perhaps.

But, I'd be curious to learn what is customary done in Haiti now, if anyone is looking at ways to build a better infrastructure for Haiti in the wake of these disasters, and whether Haiti will take any steps (legal or through market forces) to deal with these risks. I'd also be curious to see what has been done in similar places with high risks and similar concerns like Indonesia, the Philippines, India, Sri Lanka and Bangladesh.

I'm also curious how these disasters will impact the social structure of Haiti. Is it a nation where most people rent from a powerful class of landlords? If so, will those landlords be ruined now? Did they have insurance against this kind of disaster? Will tenants be able to escape leases? Will they want to or did they have favorable leases to start with? How will land tenure impact the character of redevelopment? Will it favor multi-story, but high risk tenement construction?

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